30 October 2018

A Pig and a Fork

After executing an elementary tactic in a blitz game a few days ago, I started looking for training positions for my beginning students. A rook on the seventh (or second) rank is sometimes called a pig, perhaps because of its tendency to gobble up pawns. Sometimes a weak back rank that is not fatally weak--that is, there is no checkmate--can lead to a position where a rook becomes a pig with check that also attacks a pawn. This situation occurred in my game.

Black to move

26...Qd1+ 27.Qxd1+ Rxd1 28.Kf2 Rd2+

The fork

29.Ke3 Rxb2 30.Ra4 a5 31.Ra3 Rxh2

White to move

With a two pawn advantage, Black went on to win.

I used the Manoeuvres search tab in ChessBase to find some training positions with hopes that my students could learn to play similar positions easily. My search was not narrow enough and I had to go through a hundred games to find a few of the sort that I sought. But other tactics emerged in this batch of games as well, and I filed away several positions.

This position from Euwe,M. -- Kroone,G., Amsterdam 1919 is simple enough.

White to move

32.Rc8+ Kg7 33.Rc7+ Kg6 34.Rxb7

White has restored the material balance and has healthier pawns and an active king. The effort to create threats and counterplay led Black to reduce his own rook's mobility and White won. Whether White already has a clear advantage, however, is less clear. The ending may prove instructive for my students. In particular, it was from this position that Stockfish evaluated the game as going from an advantage for White to a decisive advantage.

Black to move

Black played 38...a2. The engine sees Black holding after 38...Ra2.

White more clearly gains a decisive advantage with the maneuver in Zukertort,J. -- Pitschel,K., Paris 1878. This game also featured a queen exchange to simplify matters, as in my game.

White to move

34.Rc8+ Kg7 (other moves lead to a quick checkmate and another elementary lesson for my students.

35.Qg3+Qxg3 36.Kxg3

Black to move


And now the fork on the seventh. White won the rook ending easily, or so it seemed.

37.Rc7+ Kf6 38.Rxa7 Rxc2 39.Rd7 Rxc3+ 40.Kh4 e4

Black also has a passed pawn.

41.Rxd6+ Ke5

White to move


White let Black back into the game, but nonetheless went on to win. The lessons from this point in the game are for another day.

26 October 2018

Find the Error

Luck is what happens when preparation meets opportunity.
Wilhelm Steinitz famously claimed, "by best play on both sides a draw ought to be the legitimate result" (The Modern Chess Instructor [1889], xxxi). I introduced to my students in an after school club this week the notion that a game of chess can only be won one way: someone must make an error. The good news is that their opponents all make errors. The bad news is that they also do so.

We then proceeded to examine this game. First we went through all of the moves on the demo board without comment. Then, after resetting the pieces, I asked students for their ideas concerning Black's decisive error.

After some discussion, we went through the game again considering the consequences and alternatives where they thought they perceived error. A student earned a chess pencil for suggesting the move given a question mark by John Donaldson and Nikolay Minev, Akiba Rubinstein: Uncrowned King (1994).

Rubinstein,Akiba -- Heilmann,Ernst [D40]
Hauptturnier-A Barmen (2), 1905

1.d4 d5 2.Nf3 e6 3.c4 c5 4.e3 Nf6 5.Nc3 Nc6 6.a3

Black to move


This move's weakening of the c6 square does not look so bad until Rubinstein demonstrates how to exploit it. Even so, it had been employed by Staunton and a few others prior to this game, and has appeared since in dozens more.

After claiming that chess is a draw with best play, Steinitz lists several types of errors that can be fatal, including "the mere weakness of any square on any part of the board" (xxxi).

7.cxd5 exd5

7...Nxd5 fares somewhat better for Black than the text, but White still wins a substantial percentage.


Black to move


This move was another of our candidates for the decisive error, but it was my suggestion rather than that of a student.

P. De Saint Amant -- H. Staunton, Paris 1843 continued 8...Bb7 9.Ne5 Rc8 10.Qa4 Qc7 11.Qxa7 In analysis with the youth players, I took it as far as Black's tenth move and suggested that Black was not in as bad of shape as Heilmann found himself.

9.e4 Bd7 10.e5 Qe7 11.0–0 Ng8

One student criticized this move, but every alternative we examined seemed worse. By this point, White has a decisive advantage.

White to move

12.Nxd5 Qd8 13.Qa4 Rc8 14.Bg5 Nge7 15.dxc5 bxc5 16.Rad1 a6 17.Qxa6 Nd4 18.Nxd4 cxd4 19.Rxd4 1–0

Rubinstein was given an opportunity, but it was one that could have been overlooked had he not been prepared.

04 October 2018

Informant 137

Chess Informant 137 arrived today. While quickly thumbing through, I noticed there is a Best of Hikaru Nakamura section, as well as several other interesting looking articles, and the usual games section. Then, I installed the CD version on my notebook and started poring through the games in Milos Perunovic, "The French Combats" (83-90). This position is from a game that Perunovic references with a line ending with 13.Bd3 and White has the upper hand, Van Foreest,J. -- Christiansen, J-S., Reykjavik 2017. The CD contains the entire game.

White to move